Britax makes a Canadian parkway, which is a really nice booster, with SIP and no armrests so it is easy to buckle. That said, my DD of the same weight found it too confining and squishy for her taste (although I know some posters here who have 10 and 11 year old kids riding in parkways with no complaints), and we ended up getting the evenflo confidence. It doesn't have the sip wings of the parkway, but does have EPS foam in head, side wings and seat area, and also has no armrests, so easy to buckle. It is really adjustable, fits bigger kids well, and converts to backless. My DD still rides extremely comfortably in it at 8+ years, and 85+lbs. We have been really happy with it, but I would still prefer the parkway for the deeper wings for a younger child. There is also the compas, which is pretty good in terms of SIP, and then really the turbo is an ok booster too there is nothing wrong with a highback turbo! ...THe best is yet to come though, we are slated to have the Monterey, in April which is a FANTASTIC looking booster if you can wait that long, it is LATCHable, has great SIP and is very adjustable...HTH
