Hard plumbing with unions makes it easy for maintenance as well as support for your main overflow gate valve. Check out the pvc surface mounts on BRS, I found them very useful. If you have a tight space, hard plumb may be even easier since the flexibility is limited with flexible tubing. Solvent fitted pipe and tubing is also much more durable and does not rely on mechanical fittings, other than the unions of coarse, but those are pretty fail safe in most cases. for 1.5" sched 40 pvc, measure the distance from fitting to fitting, adding 5/8" per side. So dist between fittings + 1 1/4" inches and your done. once you cut the pvc, draw a pencil line 5/8" back on each side and insert your pipe to the line. Dry fitting (not to the lines, it will be hard to get apart) put a pencil line on the pipe and fitting for orientation. Pull back apart, apply glue, push pipe in while turning till both the 5/8" depth line on the pipe meets with the edge of the fitting, and both orientation lines are aligned.