good idea asking questions you can go any number of ways with your gear, they all have there advantages, and detractors, I would suggest reading through the 74 pages of the 60 size TF mustang thread there is a ton of ideas and suggestions there to help you on your way to a nice looking, and flying model.

as for gear I like the Century jet gear but the valves aren't the best and you can't adjust the speed unless you pay for a better one.

the 510 series of Robart's is nice but there spring down and air up,I like my gear to be retracted into the wing for storage and depending on how long you want the struts to be you end up with a short legged gear,robo struts are a little on the short side any way so you loose a little more if you have to insert the strut into the retract mech.

the 90o nylon ones work OK http://www3.towerhobbies.com/cgi-bin...?&I=LXES04&P=V I have a set in my TF Spitfire and after making sure the mounting rails are perfectly strait there pretty good and you can fit struts to them using 3/16 wire connectors,and there light weight.

then there is the LADO gear http://www.lado-tech.net/ there still a new company and there a bit slow to fill orders, but there getting better and the gear are electric actuated,the retract action is scale speed so there not snapping up into your wing like many air gear do unless you use air line restrictors.
I have a set in my Hangar-9 P-40, and another on order for my H-9 Mustang that should be delivered soon, these gear are nice,very sturdy and eleminates the need for air lines, just plug em in to your reciever and thats it no extra battery needed.
they have a 3/16 wire connector required for the struts to connect to the retract units which is a standard type connection,I used a piece of piano wire heat treated to harden it for my connecting pins works great.

so there are options,I have used all the gear but the 510 series, they all do the job well, and cost about the same + or - a few dollars, so far I am most impressed with my new LADO's for ease and sturdy construction, but the choice is yours of course keep doing your research like your doing its how I started learning about this stuff,still am.