I don't want to dissuade you, but multi effects units do not represent good value in my opinion. These units usually have dreadful overdrive / distortion sounds, synthetic modulation (chorus / flanger) sounds, and are often only good for digital delay and some additional uses (programmable, tuner, volume and expression etc)
The quality of a decent stand alone chorus will always be better. There are some mighty good distortion units which are not that pricey. Even digital delay units can be picked up cheaply (danelectro / behringer). You can buy them as you need them and as you can afford them, so I would always recommend stand alone pedal units over multi effects units. In a multi unit, the quality of each effect is compromised by being bundled together.
Behringer have recently released pedals which cost just £13!!! They are built only averagely and no doubt have very cheap components, but I bought three for test purposes, and they actually sound better than the Boss Me50 that I bought (and sold). And the Zoom unit I used was the worst sounding effect unit I've heard.
Sorry, just my experience and opinion.
If I absolutely had to buy one, I'd go for the most recent Boss unit. Although ironically, for the price, you could probably buy all the single effect units you could want.
Good luck on your purchase though
