I am about to pull the trigger on buying wheels. I just wanted one last sanity check before I drop my $$$. I have read all the posts and even emailed a few of you guys looking for some direction.

I have a 69 and I want to fill the wheel wells. With these wheels I want to put on 235/45's tires on the fronts and 255/45's on the rears. I will also be putting in a Hotchkiss 2" drop

These wheels are available from Summit

Front 17 in. x 8 in., 5 x 4.75 in. Bolt Circle, 4.5 in. Backspace
Rear 17 in. x 9.5 in., 5 x 4.75 in. Bolt Circle, 5.5 in. Backspace

What rims are you getting and from where? You might consider 17x8 (4.75" backspacing) for the front since Chevy HP magazine states a 5" backspace on a 8.5" rim, to center the same you would do 4.75" backspace on an 8" rim.

As for tires, these are my notes:

235/45 up front and 275/40 or 255/45 in rear
TireRack and Summit have Kumbo Ecsta Supra 712 (Z Rated) for cheap!
TTT-5549 235/45R17 $99.95 ($92 at tirerack)
TTT-5716 275/40R17 $121.95 ($113 at tirerack)

Kumho ECSTA 711 (High Performance Summer) 320AA ($352 shipped)
235/45HR17 - $76 at Tirerack
255/45HR17 - $80 at Tirerack

Kumho ECSTA Supra 712 (Ultra High Performance Summer) 280AA
235/45WR17 - $93 at Tirerack
255/45WR17 - $106 at Tirerack
275/40WR17 - $114 at Tirerack

Fuzion ZRi (Ultra High Performance Summer) 320AA
235/45WR17 - $96 at Tirerack
255/45WR17 - $104 at Tirerack
275/40WR17 - $111 at TireRack

I agree with Brian on the 4.75 BS on the front, that's what I ordered. I'm waiting on tires now. Here's what I have ordered and based this on what others on this site are running, (DjD) for one as he has the Hotchkis drop. Looks like you'll be dead on if you change the front bs.

front 17x8 4.75bs 235/45/17
rear 17x9.5 5.5bs 255/45/17

I am looking at the Eagle Alloy series 212 from Summit. They don't list a (4 3/4) back spacing. They have either a 4 1/2 or a 5. They also don't have them in 8 1/2 width. Will the front look dumb w/ the missing 1/4 in?

Its not so much as looking dumb but that it will not be exactly center in the wheel well. You are pushing the rim in 1/4" more. Could possibly cause a slight rub when turning and if the front suspension compresses down, on the inner well. But! I believe some have ran the 5" backspace but not positive. Search the forum.
Also maybe consider a 7.5" rim with 4.5" backspacing 7" with 4.25" backspacing?? If you do consider dropping the front size tire down to 225

Also if you go with a 5" and it becomes a problem, you can get a 1/4" spacer to push the rim out later on!

After looking around, and seeing that quite a few guys are running with a 5in BS without issue I went with the 5"BS... As you suggested this would give me the option of running w/ 1/4 spacer if needed, where as with the 4 1/2 BS I would be without options should it not fit well.

They have been ordered. Thank you all once again.