Cuff's does your rotisserie (oven) have a manual? My Ronco does and when I can get it out, I'll post what it says on a per pound timing. A marinade coating I always use on pork loin is this:

Mix Paul Newman's olive oil and vinegar salad dressing with Grey P. mustard or the other brand that has champagne in it (can't think of name) Starts with an M, I think. Anyway, just NOT a hot mustard or a regular hotdog mustard. I can't really tell you ratios but the consistency will be like a little thicker than salad dressing. Maybe the ratio is like 50/50 or so. Taste it, shouldn't be over mustardy,,just a kick. My SIL started me on this and I keep a jar of this Mustard and that salad dressing just for this marinade. Maybe for the R. oven you'll want it a little thicker but I've done mine on Rotisserie with this marinade and it comes out great. Good luck.

Just a suggestion, but pork is so lean now, that they tend to dry out, especially boneless. Try brining it in the same brine you would use for a turkey, unless of course you use some exotic brine, for your turkey. It really does help keep them moist. I have not cook one on the rotissorie, so can't help you on time. Often you can find information on the product website, so check Fabreware, to see if they might have a time guide.I personally think you might be asking a bit much to make one this size without drying out the ends before the center is done. Good luck in getting it like you want.