First my qualifications, I have been at this since my teen years in the 1970s. I have owned one store bought scope, the rest, and there is a lot, I built.
There are different kinds of "seeing", some you can do something about and others you can't. You will hear from people that will say that this or that kind of telescope is more immune. Forget it. I am not going to "re-invent the wheel", so just go here and come back when you are done reading.
Alright, now that the "seeing controversy" is cleared up, let's get down to it. I see you have a 70mm, a decent size for a beginner 'scope and later a "travel" 'scope. Consider other things more important that seeing to decide what to get. As a starting point, I would say the next size up from any given size is at least 4X wider aperture. For your 70mm that would be about 280mm. 130mm is just not going to be satisfactory. Yes, it is four times the light gathering power, but it is not even two magnitudes and it is only twice the resolution, it will barely resolve M13. I would say an 8" (203mm) Newtonian or 9" (230mm) SCT or Maksutov is the minimum. Now that you know each types advantages and disadvantages regarding local seeing from reading the above, you can concentrate on cost and portability. Yes, the bigger 'scope will show more, but if it is a 16" Dob mounted beast you are going to need to assemble and re-align every time you want to use it. Will it really show more than an 8 to 10 inch 'scope because of that? Your 70mm will get more use over the long run.
If money is the problem, download some plans from on line for a an 8" Dobsonian mounted reflector, buy a cheap saber/jigsaw and the optics and build your own. Trust me, it can be extremely rewarding. Stay with at least f/6. The eyepieces needed to perform well with say a 13" f/4 get very expensive, the same length. If you use a good tube for an 8 or 10 inch you can upgrade the mount to an equatorial made from pipe and bearings or a commercial one and you will have more to do than you thought possible. You will probably never exhaust the capabilities of 8 - 10 inches, especially after if you get into imaging and it is properly mounted for it. Many store bought 8 or 10 inch Dobsonian mounted reflectors qualify, too.
Finally, a larger aperture has to be used at higher and higher magnifications. You will hear about 30" 'scopes, but their minimum magnifications are about 160x. You will need an eyepiece with a 100 degree apparent field just to get a .63 degree true field. There is no such thing as rich field with something that big. But a 40mm eyepiece with 72 degree apparent field on an 8" f/6 for 2.5 degree true field is something to behold. I know you were not considering a huge 'scope, I am just pointing out the extremes and how someone can be disappointed with them if they do not know what they are getting into.
What do I use? My main 'scope is an 8" f/6 Newtonian on a clock driven equatorial mount. Except optics and the drive it is all home made. With a UHC or skyglow filter almost none of the NGC and many of the IC objects are not out of my reach. And there is a lot of them. Speaking of which, UHC, skyglow and especially OIII filters do not work well visually on much less than 6 to 8", you just won't have the reserve light power from anything less. So forget about 130mm with them.
I know that was a lot, I hope it was not redundant and confusing. Cheers...