Reel to reel

let’s see
@mylesastor@gregberon
I don’t know if this will work.
Myles writes for Positive Feedback and also has a chat board on audio.
Greg is a dealer--very involved in the revival of the hi-end tape phenomenon. (United Home Audio, I think is his retail brand name).
Note I misspelled Greg's last name- it is Beron. 

You can tell them you got their names from me-- not that it will make much difference. Neither sell blank tape but may be able to give you the best info on sourcing. And if you are going to dive into tape, I’d suggest you get on one or another boards with some "tapeheads"- those old machines are cool, but repair and maintenance can be a challenge. There are companies, like Greg’s, who sell what amounts to a new deck or refurbished deck. There’s all kinds of stuff, involving changing out the preamp, in addition to tape handling issue that you should know, apart from what the different options are in terms of basic machines.

I’d reach out to Myles Astor or Greg Baron, who are both into the high end 15 ips 1/2 track 1/4" playback thing of pre-recorded tapes. But, they should both know what the best current reel tape formulation is and where to get it.
A bridge I have not yet crossed---
Much as I’d love to look at a big assed Studer mastering deck in my room. :)
PS: don't mean to exclude others here who travel in those rarified circles who might have more info. 

Thumbs up for @benjie

Right. I found the ATR stuff too. Most of the tape heads I know are using it for a "higher fidelity" medium than LP (i use the quotes only because I don’t want to create an argument about whether tape is better than LP, just noting the difference in use): that tapes are available pre-recorded at a premium and some folks find old tapes, including safeties used for making records in various territories (there were a bunch of Yugoslavian tapes for sale on e-Bay a while ago- who knows what the story is on those sonically). This is different than the OP’s objective- which i remember too-- recording your albums to reel to reel, not only to save on wear but to make highlight reels (or what people today might call a mix tape or playlist).
The modern hi-end reel to reel stuff is deep and the real cost, ultimately, is source material in my estimation. One of the excuses I’ve used so far to avoid diving into that pool, much as I love the gear.
I think the comments about researching thru the tape head community are well taken though-an old machine is going to have needs. I gather Otari was a pretty good bargain deck, but don’t know.
Crazy, but Lee Perry recorded what is considered one of the very best reggae records on a TEAC - probably a 3340 or equivalent-- The Congoes, Heart of the Congo. Killer record (you need the Blood and Fire remaster, most of the others I’ve heard are pretty bad sonically, though i never heard a first Jamaican pressing-- rare and costly).
Good luck with this- could be a fun project. The ReVox and Tandberg were very common in the early -mid ’70s when I was fooling around with this stuff. Have no idea what it would cost to restore one of those machines or whether it is even worth it.

Tape from masters doesn't necessarily have summed mono bass either. It can be a killer depending on the provenance of the tape. That's the hard part. If you are having fun recording LPs knock yourself out. 

@benjie- I didn't read that review, but i've heard some of the high end decks as sources using tapes sourced from masters. Some are just spectacular. There is a very 'filled in' sound and even with a top tier turntable, less of a sense of a machine running. Greg has been at the forefront of this revival of reel to reel as a source and is a very nice guy. I don't know if Robin Wyatt still uses tape- he had a Stellavox modified by Charlie King, using a Frankenpreamp cobbled together from old Levinson parts playing a Starker performance of that Kodaly piece for solo cello over a pair of old Quads. Myles played me a bunch of tapes on his system, which is top notch- it was pretty 'whoa'- especially on complex stuff where the LP tends to get a little congested- large orchestral passages. 
@orpheus10 - since the copy can't really be better than the source it is taken from, in your case, an LP, I'm wondering if you are hearing the effects of increased gain or juiciness through the tape process, including the tape preamp.
@cleeds- clearthink did suggest that tape was inferior. 
I don't think I have much more to contribute but will watch this thread with interest. 
regards,
bill hart