you want a good 6.5 wildcat? Well look at them before you plunk down the hard cash, and also learn why and where it came from. Many wildcats are way overbore, and eat barrels almost as fast as they can make them. Yet others do very well. I like the 6.5 Ackley improved over most of the other 6.5's, and this one is easy to do. Fairly easy on barrels, and easy to load and develop loads for. the 6.5-06 is another good one, but is also getting into overbore. But if I were doing one it would be a 6.5AI with a 30 degree shoulder, instead of the normal 40 degree shoulder. Cases start out as plain jane 6mm Remington or .257 Roberts. Will push a 140 grain bullet to a tick under 3,000 fps with no pressure signs. Plenty of neck length to aid barrel life (unlike the 6.5/284 and the 260). Reamers have been ground by Dave Kiff, and there are more than one. I'd go with the one that is setup for standard .257 brass in a crush fit to aid fire forming. Just makes life easier. Another good one is the 6.5x55 improved (several versions). Should push a 140 grain bullet right close to 2900 fps.
Wildcats and improved cartridges (actually the two are slightly different but end up with the same results) came about because somebody wanted something better. Might have been throat life, or it might have been a brass flow issue. Yet another guy just wanted to go faster. But because we go faster doesn't always mean we have a good round. Probably half of Ackley's rounds were developed to end an issue with the round itself. The .220 Swift comes to mind here with it's well known brass flow issues (as well as the 22-250). Some of the improved rounds gained velocity, and a few gained very little even though the end user will often swear the bullet travels at light speed. Probably the finest wildcat ever developed was the 6PPC. Just does everything right. I won't say what the worst are, as there are several end users using them on this board.
Keep in mind that just because you make a case that holds more powder, doesn't always make it a great round. A good rule of the thumb is for a neck length of at least one full caliber, and a caliber and a half is the best. Forty degree shoulders are nice, but also have their own set of issues (dreaded doughnut for one). Yet are well known for less brass flow towards the lip of the neck. Thirty five degrees is better, but thirty degrees is probably even better. The amount of taper per inch is the end user's call. Some guys want minimum taper to reduce recoil, and others are not all that concerned. Cases that don't have a lot of taper, usually don't gain a lot from going to .010" taper per inch like Ackley so often did (.308 Winchester comes to light here), Cartridges that are into overbore, are also well known for less barrel life, and often lower accuracy. Do you need a target sized group or something to simply hunt with? Are you simply going to shoot thirty rounds a year thru it, or shoot three hundred rounds thru it?
Myself, I'd probably start out with a 6.5x47, and if I didn't like it I'd ream the chamber out to 6.5x57 Ackley off the .257 AI case.