Hi,
Ive got one of these, so far ive not found anyproblems with the standard undercarraidge seems to be fine and i take off and land in grass... althou i hate the covering it rips extremely easy [&o]
As to the MDS, i use a OS 46 LA and it flys it very well althou be warned i had to add ALOT and i mean alot of lead in the nose as it was extremely tail heavy. Also change the metal wing bolts for plastic or if you have a bump you will have no wings left
I have the vac formed undercaridge legs somewhere for retracts as i never used them, althou i would have to dig them out of my loft, soo if you do want them just let me know and ill c what i can do, but i cant promise anything u havent seen what its like up thier lol.
I hope this isnt your first kit, as i found this alot harder to build than any other kit and ive built alot............. and you will need to fuel proof the whole thing because as soon as hot fuel gets to that wallpaper covering it will come off [:@]. The Spit flys well but its very much like a warbird in flight soo be careful not to land 2 slow.. Mine doesnt fly much now as i brought a Flair Spitfire 90 ARTF (Lovely kit, fibreglass body etc etc, much much better with retracts).
Good Luck with yours