I have the same issue. One of my trucks has UE 6mm CVD's with 14mm Hex' and I'm using Dace 23mm adapters to be able to use my Pro-Line 40 series bead-loc wheels. I *LOVE* this set up but it is limited what tires are around now, although Pro-line still has a few.
At least now the 23mm wheels are cheap. I bought 8 pairs of these (why not? - it's $6 for 2 wheels!):
http://www.ebay.com/itm/Pro-Line-40-...ht_1001wt_1141
I think 17mm works fine and is strong enough, but I do like the extra strength and the look 'n feel of 23mm.