Sch 80 all the way. Hayward makes some awesome PVC bulkheads and they are a little wider which would help your issue. They even have a "long" model and you can also get them with a wide flange if needed.
http://www.haywardflowcontrol.com/pr...1_21003__Y.htm
You could probably get them ordered in through a local pool company or just find a distributor off their website.