Actually, I think you might be better off with the powder coated ones. The shop can grind the paint off the weld points in no time (5 minutes tops). Then you (or they) have far less painting to do afterward. Plus powdercoating is more durable, and would probably get better coverage too (like on top of the connector - you would have to paint that before the install!!).
BTW, I got the MM full length connectors (painted). I would recommend doing the same. The additional cost of MM (which is top of the line) from cheapo connectors is pretty negligible in the big scheme of things. Plus, you if you cheap out now, you will be stuck with those for good.
Oh and also, keep in mind that the MM full lenth connectors will be somewhat more expensive to install, because they have braces and filler pieces in all the important places. You really want all that stuff for strength and rigidity, but it does take more time to weld up. And again, the additional cost is still pretty small in the big scheme.