I have a Juwel Rio 180 with a Fluvel 205 external filter,
but the filter is on its last legs. So i am taking a proactive decision to buy a new filter before its too late,
im looking for a filter that can be easily cleaned and regulated. Does anyone have any recommendations to which i should buy?
A Fluval 05 series failure, supprise

Sorry op, but I find it quite ammusing, all week the Fluval fan boys have been telling my how reliable they are..... For a relatively quiet forum, we see posts about failures relatively regularly, but any big forum will have threads about Fluvals failing 1-2 times a week....
I assume you may want to switch brands? If so, look at;
Rena XP2 or XP3, depending on the flow you want in the tank
Eheim Pro2 2028
Tetratec EX1200
Eheim have the best Rep, but the Tetratec are very comparable to Eheim and at just over half the price... Rena are good also, if you care for the seal ring and keep a replacement handy. They never seem to fail completely, but after a while, they start to seap a small ammount IME, but otherwise are very reliable

Personally, I'd have the Tetratec, and join the "Anti-Fluval cause it failed on me far sooner than it should have" group
To be frank, the 05 series is just getting old enough to leave it's warrenty period, so you deffinately can't say yours was good at long-term reliability....
All the best
Rabbut