The sidearm should pose no special problem, unless CO laws have changed drastically in the last few months or so - check. Barring that, you must be 21+ and have a relatively clean history (I have MVs like mad, and a misdemeanour prior, and I still have no trouble in Sunny Kalifornia. I also hold CCWs in several states, and I am an instructor.)
The AR-series may be a bit more difficult, thanks to the efforts of Feinstein, Boxer, Klinton, et. al. and the 1994 Crime Bill. There are two basic configurations you are worried about - pre- and post-ban. The principal differences are the later lack of telestock, bayonet lug, and threaded barrel. Also, it is almost becoming necessary to cut the piston grip down to a "knuckle grip" to keep the knuckleheads in DC happy. Hopefully, the Crime Bill will die quietly in 2004, but I won't hold my breath... Still, it is FEDERAL law, and you will therefore be subject to it's whims.
Since you do not likely need telestock, threaded barrel, or bayo lug, don't expect it to be a huge problem. And, buying a post-ban can save you dough - something on the order of $200-600 from what I have seen sometimes.
Since you are also interested in a quality sidearm, I offer the following suggestions...
M1911/1991 and clones. .45 ACP, 5-10 shots per mag (and you really don't need that many, usually) and suitable for people like me with square paws and stubby fingers. Also terribly easy to find parts for, repair, and tune. Basically ambidextrous out of the box, requiring only one modified part to be TRULY ambi. I also recommed a "beavertail" type grip safety and a "commander" (bobbed) hammer, either or both will prevent hammer bite on the web of the thumb. Even without doing either of these, it is a minor nuisance. The slim profile is also easier to carry and not so noticable under the pillow...
H&K USP45 and Mk23 SOCOM. Both are excellent .45ACP sidearms, with double-stack mage and potential for high capacity if you really feel you need it. Suitable for those with larger palms and longer fingers, tho, as the grip is almost twice the width of the 1911. Parts not as easy to find, but is otherwise mechanically simple.
If the opportunity presents itself, borrow/rent both of these and shoot them before you decide. I have carried both, but gravitate to the 1911 for reason above. The double stack mag in the USP/Mk23 is the principal reason I don't own either - and my wife's hands are smaller than mine!
As house armourer, my cardinal rule is that my wife and I (and all regular guests) are able to use house weapons. Since I am 6'3" and left-handed and my wife is 5'2" and right-handed, this presents a challenge... Keep similar factors in mind...
FFZ