for the L260s it is just a case of bringing up the temperature a couple of degrees to 28/30, to simulate the dry season (lower water if needed too) when you can see a female is gravid or a male is showing off near a cave spawning site and the female maybe following him around. then do a 70-80% cooler water change (simulate wet season) and remember the monumental powerhead to make sure for the maximum flow and maximum oxygen levels (need it because of increased temperature. heres a link from a reknown breeder
http://www.planetcatfish.com/shanesworld/shanesworld.php?article_id=98. also heres a link of an article iput together from different sources that will help with the cave sizes and for general breeding of hypancistrus
http://www.monsterfishkeepers.com/forums/showthread.php?t=30161
Not many people have suceeded breeding royals, but i have read it has been done in a reasonably large tank using long pipes for a breeding site. they simulated the dry season with low water levels increased temp and keeping the water relatively still for a couple of weeks and then filling up the 70-80% with cooler "rainwater" and they spawned in a few days. it might work for you if you have smaller sp. of royals, cant remember which ones you had, but this attempt might be a long shot.
well the ancistrus sp. will be no problem for you. heres some info i gave ages ago, and its pretty much what i did with sucess
http://www.monsterfishkeepers.com/forums/showthread.php?t=20660&highlight=breeding+ancistrus it has some other links on there too for more info, i have personally used the second one.
for your L262s it is pretty much the same (if not identicle) to breeding your arabesque, as they are closely related fish and come from the same river so just do the same for the two.
the L200s hmm thats more tough. it has been done, but not by many people at all. all i can tell you for sure is they are most probably a cave breeder, and id just try the same kind of thing with them as you do the hypancistrus. you can always talk L200s with wyldfya lol.
for the peckoltia L134 i suggest you read this article, its another one of jannes -
http://www.planetcatfish.com/shanesworld/shanesworld.php?article_id=241 fantastic article imo.
If your clown is panaque maccus, it should be easy to breed, just the whole dry season wet season duo, but heres a snippit from planetcatfish-
"The fish should be maintained for two months under dry season conditions (see above) with thrice weekly feedings of frozen foods. In preparation for breeding, add a power head and air stone to the tank, unplug the heater, and begin making 20 percent daily water changes with cool rain or reverse osmosis water. The temperature should be allowed to fall to 70-72F. After four water changes, plug the heater back in and wait for the spawn. If, after one month, the fish have not spawned start the process over again. It may take a few cycles to get the fish spawning. Provide various sized spawning caves made from PVC or slate. The caves should be just large enough to allow the female (which is larger) to squeeze in and five to six inches in length."
A few things, it would probably be better to try and do them in separate breeding tanks, but some like the p. maccus and hypancistrus, you could probably do them together- might get crosses though!
If they are cave breeders, it is good for the caves to be a tight fit for the two adults.
Please remember FOOD. This is pretty damn important when breeding, be sure to feed lots of veg and meat and lots of it. Keep ‘em happy and then you’ll be ok!
Hope this all helps, good luck steve