So you have difficulty holding down the ruler, but you're still okay with pressing on a rotary cutter? Seems to me you may eventually have problems with that too.
I have both the Stripology and June Tailor mats. The June Tailor mats work well for me with the Guidelines for Quilting strips underneath them:
https://www.amazon.com/gp/product/B009DF9DLA/ . You still need to press down on the mats somewhat to keep them from slipping, but the strips make this very easy.
People either love or don't-love the Stripology ruler. I'm in the don't-love category. I would suggest trying a single June Tailor mat first, with the Guideline strips on it, to see if this kind of mat will work well for you, before investing in Stripology or other mats. All mats still require some pushing down to prevent slipping.
What I absolutely ***love***, that you haven't mentioned, are the Quilter's Slidelock rulers:
http://www.quiltersslidelock.com/ . These might be rulers you could use, as (1) the wooden handle is really easy to push down on, and (2) the grippers that engage when you push down on the handle keep the ruler from slipping. I would recommend trying these before giving up on rulers altogether.
I have seen mixed reviews about the Alto. Personally, I think I would find it aggravating to use so this would be a last resort for me. It takes up quite a bit of space, I think. Some people love it, but others definitely do not. Are you a member of a local quilt guild? I'm thinking you might want to ask if someone in your guild has one you could try out.
Honestly, my recommendation would be the Accuquilt Go! Big electric. As Ragamuffin pointed out, you could sell your manual Go! to help finance the electric model. Plus, I'm hoping there might be some good Black Friday sales that include the electric. You could use all of your existing dies in the electric machine. Plus, this is the only option you mentioned that includes the possibility of applique. I use Go! dies to cut freezer paper for invisible machine applique. For a special project, it's possible to special order a die of your own design. I personally do not like to use the Go! strip dies; the June Tailor mats work better for me.
No one device is going to be perfect. For example, the Alto and the rulers you mentioned are suitable only for geometric designs. You still would need something else for applique. In my opinion, the Go! electric is your most versatile choice. In terms of the dies, I would buy dies only for your current project. That keeps yearly costs down. I have a stockpile of dies I haven't yet had time to use. Wish I would have simply invested in one project at a time.