Start with a Tactical CAR A4...get the model without carry handle/mount. Sub in the stainless bbl, sub the M73 handguard, order a flip rear sight andother accessories as inclined.
Stainless 1:8 vs Chrome-lined or Moly 1:9? Stainless is going to be silver, so if the subdued tactical look is what you're hoping for, it won't be. Aside from that, you'll pick up a little better accuracy across a wider range of heavier bullets with the 1:8, but lose a little bit of the selection from the lighter bullets. Generally 1:9 is good for 55gr-69gr (approximately, different bullet profiles will make this go one way or the other a little bit), while the 1:8 does better with 62gr and up (I'm personally getting the best results with 69gr to 75gr)but, again, it depends onthe actual bullet. The 3/4 MOA won't nec be there without free-floating the barrel, even with the stainless upgrade, however.
When it gets closer to the time you want to buy, let me know. We have quite a few new items coming out in our new catalog, along with some accessories that are no longer going to be included. Watch our web site right around the 9th of February for the big update that coincides witht he release of the new catalog at the SHOT Show.