These matches will be hosted in Guyana and St.Kitts, none of which will have a wicket offering assistance to quicker bowlers for any significant duration over 5 days (if any at all). Hence if we must take 20 wickets to win those matches, we must consider starting with 2 spinners and 2 out-and-out quick bowlers.
My bowling attack would be:
1)Rampaul
2)Roach/Edwards
3)Bishoo
4)Austin
Yes, I'd go with a leggie and an offie for variation. IMO, having a leggie and a left-arm orthodox spinner gives almost the same effect in the spin department, hence compromising variation.
Ideally, I'd love to have a GOOD bowling allrounder to bolster the bowling department. So I would have choosen any one of Carlos Brathwaite/Riad Emrit/Dave Bernard, however since Sammy is an automatic pick, he's going to have to play that allrounder role.

No doubt, with him in the squad our ability to bowl out teams will be significantly diminished (still hopeful that he proves me wrong for the sake of the team though).