So, i am making a new forum, from what i have seen, there's none like this around, i am wondering what software you think would be the best, i want to make the site look very professional, if i go with PhpBB i will need a mod installer, so i am trying to get away from that one, otherwise, what do you think is the best?
Well I'm currently using SMF for my forum and it seems to be working nicely for me, so I'd recommend that. If you use it though, don't do what I did and get the 2.x version that is in "beta", since most mods are compatible for it while not really that much for others.
There is an auto mod installer (Blinky) for phpBB3 which will install mods for you but i always find installing mods yourself better. It means you can see what you are adding and you learn yourself how the forum works and basically you teach yourself to understand php which is useful when running a forum as if something goes wrong there is more chance of you fixing it. You know what was edited and you can understand what might be causing an issue. Automatic installers can install things and leave you with no idea what it has done and edited.
I see your forum as your business front. If you are going to open a store, or a business, do you want to look professional? Or do you want to look like your trying to get off as cheap as possible?
Using a free forum software isn't being cheap nor un-professional. You can customize Mybb 100% to make it look professional. Plus, it saves you about 180+ USD - so you can use that for hosting, advertising, or most importantly the design of the forum.