id also try to maybe get a peice of bogwood and tie them on to that with some string. It takes a little while but the plants eventually get stuck on to the wood and you can cut the string off or just let it decompose naturally...takes a bit longer though. if you do decide to do that do it with a colour string that doesnt show up like black or brown just for a nicer look while they get their root. it may take a couple months or so but different plants different speeds. how much light are you planning on putting on them? it sort of depends/limits what plants you can put in the tank. id first figure that out. heres a link for that
here is a short form with basic break down as to what level
WPG = what level of light as commonly accepted
http://www.thekrib.com/Plants/Tech/Lighting/
differing levels for differing tanks
this table is adjusted to achive the desired level of light "watts/m2"
and accounts for the breakdown in smaller and larger tanks.
IE a 10g to achive lowlight needs 2.4 WPG the same level in a 50g = 1.4
etc.
once you get the lighting down see what you can possibly plant, this website will help a bit
http://www.plantgeek.net/
then id write a list of things that you like the look of and go to your store and see what they have since not all places have the best selection. my sugestion is that dont by something at first just find out what they have. if you didnt find it on that website then check out the rest of the web. once you have a good list id break them up to background, foreground mid ext.. then draw a plan of what you want your aquarium to look like with the plants that are avaliable to you as well as the other decor you have.
I know that all seams like a lot for just wanting to get some plants in but it gives you a much nicer look in the end and you at least have an idea of what your going for vs crazy wildness... on that note i may look up some other 55 gal setups to see what you like out there and take some ideas.
sorry for the book but i wish i had done so, but then again all depends on what type of look your going for.
oh and some nice redish colour plant is sunset hygro its not fully red but nice touch
and heres a link for that and some people comments
http://www.aquahobby.com/garden/e_Hy...Rosanervig.php
....sorry for the book.
best of luck with the new tank, should be a fun one.
tom