I'm by no means an expert but hopefully this basic info will help. Most of it came from other owners and also from my own mistakes and good choices in engine selection.
No matter what size of modified engine you select the most important thing is ensuring that good parts are a part of the longblock (case) selection:
Get a good case (new). A new AS41 is the basic thing I would look for in any builders list. You can also opt for an AL case from CB, but for non-stroker combos it would not make sense, plus the cost is more.
A good quality balanced crank is essential. Many of the low budget engines you see advertised do not include this, or the new case.
New rods, new cam & new valve train parts are something I think are basics for a hi-po engine. Do a search on engines here and you will find differing opinions on what parts to use... but there is little arguement on the need for quality internals.
Spend the money on heads.... whether they are reworked VWs or aftermarket units such as CBs different selections.
Use a good engine builder that others recommend.... listen to what they suggest and go with their recommendations. Besides good parts, it is important that the parts go together in a combo that is balanced for your needs. Tell the builder your expectations, driving habits, and planned usage.
Several builders have pre-packaged selections.... and I don't know of any good quaility builder that offers a complete package for the price you listed. You do pay for what you get in most cases.
I have had outstanding luck with a CB Performance 2110 engine with over 17,000 miles on it now. I also drove a solid 1776 from Jeff Gervais (google his name with VW) that now has over 25,000 miles on it and is still going strong for it's second owner. It cost a little more than what you will see in HVW ads by some builders, but in terms of reliability and satisfaction it was worth the extra $700-800 to get a balanced crank, new case, the right heads and cam, etc. There are other good builders.... and I'm sure owners will share them with you. I listed CB and Gervais because of my personal experience.
I'm one of those (if you do a search) that is not so high on the so called mexi-crate engines. Others have had good luck with them.... but for a high performance application, well..... I lost a mexi-1776 when a cast crapola cam gear sheared off the cheap cam gear bolts, and the engine imploded... continuing it's destruction of the cheap crank. This was on an engine with less than 4 months on it, properly maintained, not abused, and happened at 3500-400 RPms in 4th gear. Again some have had better luck with them, others have not. Take your chances.
Carb selection should be done by your builder... imo. There are many capable people on this forum that can build an engine and dial in the carb jetting, floats, etc from long time experience. That's good. But, at my level of expertise I'm more comfortable with having them set up, or at least using the experince of other owners when setting up carbs.
Get an external oil cooler/fan/stat unless you live in Anchorage.
That's it. Do a search and you will find hundreds of posts on this subject with much better info and in-depth advice.
My experience has been only with 1776s and 2110s. Other's will wieigh in with their suggestions on diffrent crank/piston combos.