For visual a 1.25" wedge is good enough, if your scope is under 4". Above that and for extended viewing, a 2" wedge is recommended as the heat trap is bigger and able to absorb more heat. There is slightly more contrast when you use a wedge Vs the Baader solar film.
I have used both and I have both a wedge and Baader Solar filter - wedge for visual, solar film for imaging. For imaging, if you get a wedge and try to use a DSLR, if in your choice of a refractor, the weight of the wedge and the camera on top of it does not present problems for the focuser and / or mount, then the wedge is better. If there are issues such as I mention, then a Baader solar film with appropriate filtering would be better.
You should use a UV/IR filter if you go for the solar film as the Baader solar filter does let in a bit of UV. Actually when using Baader solar film for visual as well, a UV/IR filter would be beneficial as despite the fact that the glass of the refractor will filter most of it, there might be some small leakage of UV.
The Baader Solar Continuum filter provides even more contrast instead of the UV/IR and it is also coated for UV/IR. Also can be used with a Wedge (I have mine permanently fitted in my wedge). You CAN use the Baader ND5.0 visual filter for both imaging and visual (no need to get the ND3.8 separately - that's solely for imaging by the way). At around F10 - f12 (before considering so called "crop factor") which is where I have my fun with the sun, I have not had any issues needing more photographic speed or increasing ISO beyond 100.
Choice of scope: I have found that a 90mm f10 achromat will perform just fine. A shorter doublet ED will make mounting perhaps a bit easier (depends on what mount you plan to use) since it will be shorter f ratio and hence shorter in physical length. A triplet will not provide much perceived benefit, but hey, buy once "the good stuff" and feel the pain only once .
Since you need a travel scope, and you are using either a crop or full sensor, I would recommend a doublet in the 80mm f6 category and a barlow properly distanced to the DSLR sensor to get to f12 - f14, plus your choice of Alt/Az mount with no tracking (say a Porta Mount or AZ4 or AZ5 or something in that category).
Note that your ultimate focal ratio should be more or less such that you have the sun in the FOV of the camera with a bit of "free" space around it, so your choice of a crop Vs full sensor will affect this. If you use a full frame camera, you can push the magnification higher before you fill the FOV, hence you will need something with a longer focal length, but with a reasonable focal ratio. For full frame I would recommend a 90mm to 100mm f7 and barlow to get to f12 - f14 (before considering "crop factor).
I attach an example using a 90mm F10 achromat with a Nikon D5500 (crop frame) at prime focus just to show that an achro is not shabby at all. My processing skills at that time (a couple of years ago) were not much to talk about so take it with a pinch of salt.