You could build both and interchange them like you said or you could just build a bubbler and be done with it :handgestures-thumbupleft: Have a look through the stills section and see what takes your fancy. Building really isn't that hard and a lot of blokes here who'd never touched a blow torch have successfully built stills. You don't need alot of tools and basic ones at that.
Here's a few to get you started, there's plenty more in the tips from the work bench section. These threads are where I learnt to build stills, they're absolute gold :handgestures-thumbupleft:
viewtopic.php?f=41&t=76viewtopic.php?f=41&t=11390viewtopic.php?f=41&t=1237viewtopic.php?f=41&t=3087There is also a video on how to build a shotgun condenser in the site donors area so if your keen to see it hit the donate button down the bottom of the page, donate $20 and you'll even get a nice blue jacket to go with it :handgestures-thumbupleft:
Just a small tip mate, take your time and don't rush in. it may take a few days or even weeks (I read every page of every thread in the plated column section before I built my bubbler) of reading threads to work out what suits you but it will be worth it when you build/buy the right still for you and not just some artifact that hangs on the wall like my first 2 stills.