The hourly costs at cpl/ir level are pretty high. You don't want training to over run if you can help it. Anything that helps you learn quickly and get that first time pass is best, more time on the complex aircraft, more time on the twin, a sim that closely matches the aircraft etc..
Have a chat on the phone, pay them a visit, hang around, chat to a couple of current students, get a feel for the place. Look for a school that specialises in cpl/ir rather than a school that has the approvals, but doesn't actually do much cpl/ir training.
My first stop for an IR school was one based at a caa test centre airfield . Positioning a twin for ir test and if unlucky a partial or retest all adds to the bill...