Personally, if you have the money to get a Juwel Vision260, I'd go for the Juwel RIO300 instead - it gives MUCH more space at the bottom for another 5 cm of "width" (51 cm vs. 46 - but the vision is curved, and the "ends" is a good 7-10cm less than the middle, hence smaller capactiy and smaller bottom-space], and it costs less [at least at
www.thegoldfishbowl.co.uk, which is where I got my RIO400 from].
There isn't a HUGE difference in tank-size -the RIO300 would take tiny bit bigger fish, but nothing that you'd say "Oh, if I buy this one, I can get something completely different" - all of the tanks are suitable for the smaller types of L-numbers, e.g.
,
,
, etc. These generally stay below 20cm/8", so they are fine in either tank. There are a FEW fishes that would creep into the viable size ONLY in the RIO300. The general rule is that the tank should be at the very least 4L x 2L x 2L, which means that the max size of the fish is half the shortest side or a quarter of the longest side of the tank, whichever is smaller.
If money is tight, I'd probably spend it on the Fluval 1000 tank - I had a Fluval 800 until recently (replaced by made-to-measure tanks to fit my racks). Only slight drawback is that compared to the RIO300, the filter is a lot more maintenance - it's a good filter as long as it's kept clean. Plecos tend to make a fair bit of mess, especially if you have succeeded in breeding them and have a bunch of juveniles needing a lot of food.
For a beginner, if your goal is to breed plecos, I'd definitely recommend to start with a common
- they are very easy to keep, and easy to breed. Once you've had a bit of practice with them, you can get something a bit harder to breed -
(or other Sturisoma species) will test your fry-care skills, even if getting them to spawn isn't too hard.
would be a good starter for the second level of skill as well.
Note that looking after the fry once the fish has spawned is part of the learning curve - so it's good to practice on fish that spawn relatively easy before you go for the "big hitters" that only spawn perhaps 15 eggs once a year - you'd be kicking yourself quite a bit if you got a spawn, and then accidentally killed the fry by some simple mistake.
Once you've mastered that, you can probably "attack" any species you like - although it is obviously easier to go after those species that have been bred by many than those that have "no breeding recorded".
As to flow-rate, caves, feeding, etc, it's fairly hard to be specific unless you have decided on the fish itself.
There are lots of breeding articles for all sorts of plecos in the Shane's World section of this web-site. Have a read of that.
Once you have decided which tank to go for, which species of fish, etc, and if you still have questions, please feel free to ask again. But it's very hard to give advice without also knowing what species (or at least genus) we are talking of.
Also, bear in mind that it's all well and good looking at the
Specialancistrus unobtanious in the cat-eLog, but if your local shops can't get it, all you will ever do is look at the pictures on a web-site. For sure, ask your local shop what they can get, how much it is, etc. But if it's impossible to get hold of, then you'll have to look for alternatives. In general, fish with many keepers (listed as "k:xx", xx being a number, in the Cat-eLog listings) is easier to find than those with "k:0" or "k:2".
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Mats
, im just wondering if anyone can give me advise on this. I may be able to get a Jewel Lido120, Jewel 260 or Fluval duo 1000. 
So for each one what pleco would you recomend for a beginer, plz include tank layout, feeding regime and amount of flow. 
Sory if i'm asking for two much! 
What I plan to is to spawn and raise the fry atleast a half dozen times, with 90% of the fry surviving, before I even attempt breeding a Hypancistrus 
) so now i'm been offered a preowned rio 300 n a vision 260 n i'm wanting to build up a colony of Hyspanistrus.sp 
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