Btstrg, from what I know (and I could be wrong), the LS-15 does not have a phono stage built-in. The SP-14 is one of the "hybrid" models. At least one commentary I've seen disparages the power supply but I would do a search of the archives to find users' experiences. An SP-14 would likely be more money than any of the lower 'even-numbered' SPs (SP-6, -8, -10) or the SP-11 because the lower numbered ones are 10+yrs older. I'd personally prefer a -10/-11/-8/-6 in that order if all the same price. These will be especially good deals if they have been 'refreshed' (capacitors replaced, etc) by the factory or modder recently. A similarly "scary-good-for-the-price" old preamp with phono, IMHO, would be a "refreshed" Counterpoint pre with separate power supply. Every now and then they come up on Audiogon and if I didn't already have something which needed refreshing, I'd definitely consider one myself.
The other route would be to go for something which was 'just a phono stage' (which means that if you ever wanted to put a preamp between your CDP and amp, you'd be outtaluck), in which case you might get something with a smaller footprint and good dedicated phono stage for similar money or up to 30-50% more.
Biggest problem with any of these older choices is that it would be tough to demo before buying used unless at a b&m dealer...