Just bought Martin Logan Vantage speakers.

You may want to ask the question here

http://www.martinloganowners.com/~tdacquis/forum/

I'd go with a separate pre amp and power amp. You'll need a amp that is stable to 1 ohm with lots of current.

Try Mcintosh MA2275.

These are Martin Logans, no Apogees. They are a 4 ohm load and are fairly easy to drive. I was temporary driving them with a 45 watt Parasound Zamp while I was waiting for my big amp to arrive.

From the Vantage manual:

What size amplifier should I use?
We recommend an amplifier with 100 to 200 watts
per channel for most applications. Probably less would
be adequate for our smaller hybrids or when used in
home theater where a subwoofer is employed. Our
hybrid designs will perform well with either a tube or
transistorized amplifier, and will reveal the sonic character
of either type. However, it is important that the
amplifier be stable operating into varying impedance
loads: an ideally stable amplifier will typically be able
to deliver nearly twice its rated wattage into 4 Ohms
and should again increase into 2 Ohms.

Remember, the Vantages come "pre-biamped": their woofer is driven by a built-in SS Class D amp. The (external) amp (or 'amp section' of an integrated or receiver unit) that you choose is therefore only driving the electrostatic panel. And for my money, there is no sweeter, more articulate reproduction than electrostat + tube amp. I can't off the top of my head think of any contemporary tube output receivers (tuner + preamp + amp) although there are a lot of vintage ones to choose from. If you would consider an integrated amp (preamp + amp, no tuner) there are certainly a dozen or more high quality ones available.

McIntosh amps (like the MA2275 integrated Barnes mentioned) are particularly well-suited to driving electrostats because they use an exclusive circuit that makes their output "current-controlled" rather than the more conventional "voltage-controlled" arrangement. Electrostats like that (a lot!) and it mitigates the drop in impedance typical of electrostats (usually at high frequencies.) 100W/ch is more than enough to drive a pair of Vantage panels, and many Vantage owners use a Mac MA2275, or (just amps) MC275, or MC2102. The last two can be bridged to mono if desired (then you'll need two of them!) but it's unnecessary IMO unless one day you move up to Summits . . . .
.

I totally upgraded the Vantage Xover which is a huge improvement.I was using a Audyssey plus amplifier and it sounded pretty decent .My brother brought over a Ayon
Triton mk2 for a few hours and WOW it was one of the best
sonic treats I have Ever heard I guess stats love a Great tube amp and the Ayon is for sure one of the best under $20k out there currently this integraded is around $9k with discounts .I am looking to get one after the holidays
it is now hard to listen to SS after hearing the ML Vantage with tubes .

It has been a while but I had a very bad experience with an NAD receiver and then with the difficult process of getting it replaced. That being said, the NAD sound was quite good for a receiver. Someone I know was just telling me how much he loved his NAD integrated and had never had any issues. I would look for an integrated or separates that have the drive needed for your speakers. You should have some good options in your budget range. Maybe MF kW500.

As for me, I'm using Caiyin CS100A integrated amplifier with 6550EH power tube (ultra linear mode).
I feel the Caiyin provide an excellent match with ML Vantage. Smooth and detail mid & high freq. Bass is good and reasonably tight (for a tube amp).

For those of you who are on a Budget and prefer vacuum tube amp to drive the vantage, I think Caiyin CS100A is seriously worth a consideration.