I spent a while researching this because we’re redoing our website as well.
We ended up going with an e-commerce platform that was specifically built for printers and it includes a personalization module.
Some of the other ones I was looking into were PitchPrint (plug-in for Wordpress sites) and Chili Publisher (good but very expensive).
There’s also HP’s Application Center, which used to be called Wall Art Suite, but it’s only for wide format and can’t really be used in conjunction with other platforms so it didn’t work out for us. Hopefully we’ll get to the point where we can have a dedicated website for wide format so that we can use HPs platform because I thought it was really, really nice.