One thing to take into account in your situation would be resale/repair both in your country of residence and your home country. You don't say where you're going to school (US? Europe?), nor where you will be taking the amp back to (Asia? Europe? The Americas?), but if you're buying something new, you ideally want to buy something with distribution in both countries and an internationally valid guarantee. That may put you off some "boutique" brands. Are the AC current standards different between your country of residence and your eventual country of return? I was living in France when I bought my EBS Drome, and had to swap out part of the power supply when I moved to the US - fortunately, the EBS engineers are amazing and made this a cheap and easy, no-solder operation. Some amps are 110/220V switchable without modification. Others require a conversion that can be far more costly and complicated than mine was.
You don't give the model number for you Ibanez amp, but while some combo amps have a line to go out to an expansion speaker, it's pretty rare for them to provide an input to use the combo as a speaker as you describe. And even if it did, you probably couldn't play much louder through it than you can with it's built-in amp - it's doubtful that anyone would fit a 200W-capable speaker in a 25W combo. If you're going to upgrade, you're either going to need to buy a head and a cabinet, or a new combo. I don't go with the school that says combos are always a bad investment, but in your case, keeping them separate may be a Good Idea. You may find that only one or the other is really worth shipping home. And the new generation of very compact solid-state bass heads are things you could carry in a suitcase, and air-freight back to a distant factory, if necessary, more cheaply than traditional heads.
I haven't touched on any brand/model recommendations here because I think in your case other practical issues take precedence over subtleties of tone color and packaging.
thank you!
