I personally like the Edelbrock a bit better than the Offy (the Offy is a single plane design) that being said I am running an Offy because that is what I have and I know that there is room to adapt it to a large base center carb.

I've never tried re-coloring (although I'll occasionally hit the base plate with a light coat of flat black paint). In the past I've have been lucky enough to find carbs that had a pretty unifom finish for the set.......but as mentioned in my first post it's getting a bit harder to be picky. I've heard good and bad Eastwoods system...the bad, mostly that if you ever spray them with Carb Cleaner the finish goes away. I would be very hesitant to powder coat the carb. The curing temp is 500 degrees and I'd be concerned about warpage on the center and top and on modified base plates you would run the chance of either melting the soder out fuel passages or re-sodering them after and hurting the finish. I have often wondered about having them tumbeled but never got beyond the wondering part.

Manifold finishes......I had a friend who did powder coating for a while some of the near chrome finishes didn't look too bad, but they didn;t look chrome. Best sugestion would be to have them do a sample part for you to look at before you send the manifold and see how you like it. Yes it will discolor slightly at the heat crossover....but that only proves you drive it.

Personally I prefer a natural aluminum finish on my intakes but will not clear them. If you drive the cars (mine usually get several thousand miles a year put on them). Clear will work for something that only gets used once in a while but will yellow over the years and if you do use carb cleaner on it it goes away. A few cans of carb cleaner on a natural manifold and it will look like new even after number of years (especially if you keep up with it). If you want shiney on the intake I still think your best bet (and most labor intensive) is to polish it.

As far as blocking off the heat riser my opinion is that it's a bad idea unless you never plan on driving the car unlesss it's a nice warm day. Again I drive mine frequently. It's not unusual for me to pull one out to drive to work on a winter morning and it 15-20 degrees (it will usually be 70 in the afternoon........love AZ). If there is any chance of driving in weather below 40 degrees leave the heat riser open.