Hey guys,

first of all some information. I played in a band for almost 4 years. For gigs I allways borrowed an amphead from a friend. Usually you don't need to bring any cabinets for gigs as they are supplied by the promoter. Also the guys from the band had a bass combo amp for band practice at the rehearsal room. Since I only play for about 5 years I never had the duty to buy an amp. All I have is my small practice amp at home. I am joining another band in the near future. Those guys are playing some mid sized gigs and small festivals, so I need a good amp for rehearsal and eventually for gigging (as I don't want to bother my friend anymore...).

I need an amp for rehearsal and small to mid sized gigs/ small festivals.

This one is the amp of choice. I played it once at a gig and lately at a local musicstore. It fits perfect.

The question is, should I really get the 5500 version, or is the 3500 strong enough for my needs, because I don't have that much money.

In addition whats about the speaker/cabinet I need? How much watts @ how many ohms will I need? Physics aren't my thing, should it be equal to the amp head? Stronger or weaker, somewhere I read something about 'overhead'...?

Would this one do it?
500 Watts @ 4 Ohm vs. 300 Watts @8 Ohm
I guess not.

Don't forget I have a pretty small budget. ~800€
Thanks for help and advice.
that combination should do the trick. It will be loud enough. 10 inch speakers tend to produce lots of mids which are ideal for a bass cutting through the mix. And don't worry about it not producing lows because it will!
And if you want to get the max out of the amp you should buy a 15 inch cab in the future to finish the stack! Than it will go sublow and loud as hell!
To set things clear, the 3500 version should be enough for my purposes? You didn't specify that. And also could someone comment the watts/ohm issue? Even if I choose the weaker one, I would like to know how that works.

Thanks in advance.
Yes many pros have used that head. It really puts out way more power than it is rated. its peak output is almost double what the RMS is.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate