You don't need to modify the ailerons. If your friend's Skybolt had a slow roll rate, he was using low control throws (or has large gaps)

An Ailerons effectiveness greatly decreases as it nears the center of the wing. By making them 50% longer, you may gain an extra 5%. Just go with the option of putting ailerons on both wings and seal the gaps - You will have MORE than enough roll rate.

As for the cabane and the end struts, they are one of the best features of the GP Skybolt. Just do them exactly as shown in the manual and you will have no problem. Whatever you do, MAKE NO MODS THERE!!! That system is the BEST that I have ever seen! I only wish I could modify Every Bipe that I have ever owned to use the same system! It works great, and it sets up faster than any system that I have ever used.

BTW, in case you haven't seen it, here's my old Skybolt:

[link=http://204.96.183.34/Skybolt/Videos/skybolt_high_res.wmv]Skybolt Video[/link]