Remington LTR, SPS Tactical, or PSS. The sps tactical would run you around 550-600ish and then you could sell the Hogue stock thats on it for 65-75 bucks then have round 350 ish for a stock wether it be a HS Precision, Bell and Carlson, or the Choate Tactical.

My advice for you to achieve maximum bang:buck ratio is to get yourself a bedpan and get comfortable on the FS forums.

I think we have all seen some nice rifles go for very reasonable price on there.

+1
this is the real answer. Most of the high-end tactical rifles are so similar they could be twins. Decide on your caliber, research different custom actions, then wait for the right rifle to appear for sale. This will be much quicker than building a custom rifle from scratch and you'll save a chunk of change as well.

If you want to go cheaper than a used custom, buy a used factory rifle and put a top-flight custom barrel on it. That is all you really need to have a shooter. Heck most good factory guns shoot 1MOA anyway....now why did I spend all that money on my custom rig?

Slight update...
paid for a used 5-25x PH from the for sale forums here.

I was almost committed to getting an AICS 1.5 and placing a Remington 700 5-R in there. After all is said and done... it'd be about $1500.

But I've been told to save some cash and look at the Bell and Carlson Tactical Medalist A5 stock as it's very similar to the McMillan A5 for cheaper and without the 6 month wait.

I was thinking about getting a SPS Tactical and selling the stock (Roughly $500), getting a B&C A5 (Roughly $400), getting the action/bolt trued ($250), and then getting it all bedded ($200). So the total would be about $1400.

Would the SPS Tactical with custom work shoot much better than the factory 5R in an AICS?

That's easy:
Remington 700P or 5R
Get it tuned up(action trued, etc) and bed the stock and shoot it until you have tried other stocks. A USO SN or ST series scope(SN3's kick ass!) with a set of USO's MkIII rings on a USO Base and you will be straight, and all in a one stop shop trip.

I have both the MCMillan A5, and AI stocks on my rifles. The AI is butt ugly and looked really uncomfortable when I first saw it, then I shot it. Nice! I love my PSS/A5 and I love my GAP/AI but that GAP AI will shoot small groups all around my PSS if I do my part long after 40 rounds. The PSS, well she stays tight, but after about 40 she opens up a wee bit to between 3/4 and 1 MOA out farther.

But do yourself a bug facor, spend the money tuning the rifle's action etc and shoot it in the oem stock. When you get ral good at shooting the rifle, you will have hopefully hooked up with other Hide members and shot other stocks to see what you like. By then, you will be ready for a new stock, and a new custom barrel.

That is the course I was going to take when I got my PSS way back when, and things kind of fell into my lap from some really cool people here. The best way I have foun to thank them is to do what I can to bring interest into our sport at my local range. My rifles tend to get a lot of looks and questions, and I always make the offer to teach a few people how to shoot it. When they feel that Kelly McMillan Special A5, and look through that USO glass, I cannot help but stand back, smile, and keep thanking whatever it was that brought me here.