Besides an arch, have you thought about a wakeboard tower or simular? You can get fixed hardtop canvas binimis from those as well, the ability to mount things up there etc. Might be cheaper, and they custom make it anyway in stainless or aluminum so you can get something what you want. You can have it tilt forward or back.
Just a thought.
2012 - Regal 35 Sports Coupe - Twin VP 5.7GiCE-300-P - DP-SA
2011 - Sea-Doo RXT260s - 1503HO Rotax 4TEC
2007 - Regal 3060 - Twin VP 5.0OSi - XDP
2002 - Crownline 230BR VP 8.2GSiPEFS - DP-SM
2001 - Polaris Genesis I - 1200DI