That was the problem i had with the Nero LX, after buying 2 fairly expensive heatsinks, i wasn't going to buy another so i ended up grinding around 30mm of the one side of the Nero so i could keep the fast RAM.
Patriot Venom Red, that's what you have right?
It's 41mm tall so the AXP-200 won't work with that (maximum memory height of 33mm supported)
I'd avoid an AIO. you want some airflow over the board or the VRM's will get hot and cause throttling.
Another option is to replace (or remove) the heat spreaders on the ram, freeing up your choice in coolers.
Memory heatsinks are just a gimmick these days anyway DDR3 doesn't get hot enough to warrant the use of heatsinks.
Take Samsung Green for example some of the best overclocking, low profile DDR3 ever made and it uses no heatsinks.
Sadly it won't clock over DDR3 1866 in the Gigabyte board as it has a DDR3 1600 XMP profile and the Gigabyte A88XN-WIFI hates manual memory overclocking on the bios's available.
I've got 2 sets here both capable of well over DDR3 2600 and can't use them in the board at anything over DDR3 1866.
Or you can just be satisfied with what you have and understand if you want higher clocks, you're just going to have to throw more money at it.
That Akasa Nero LX was never going to be any good for overclocking even before you chopped some off it.