makmov, I'll add a couple comments to my 'other'.

Using the reference 'war bird' loosely, the Park Zone Corsair is a great flier. However, it doesn't in any way IMO prepare one for flying a larger War Bird that is more true to scale. These generally have higher wing loading (detail, retracts, and extra functions all add weight), large wings, and a smaller tail than any aerobatic or sport plane, a fighter like airfoil.

An AT6 was a full scale trainer for war birds, and is also a good model scale trainer for many of the same reasons. It has that war bird shape (big wing, little tail) that dictates a war bird-like take-off and approach procedure, yet is more forgiving than most war birds in flight.

As you experienced, a fighter must be flown to the ground not floated in like an aerobat (like your Ultimate). A higher steeper approach under some throttle with a well timed flair just above the ground works best. Flaps are almost a necessity to break speed on that steep final with giant scale fighters, but the 60 to 90 size usually are fine without them. They don't have the wing loading that most highly detailed and gas powered giants do.

I'll agree that the Top Flight P-47 is a good choice after some stick time with a smaller and lighter trainer like the AT6, but really, unless you get into a more true to scale warbird (both in wing loading and airfoil) like a Zirolli, there a many modified fighters out there that are designed to be stand-off scale yet be easy to fly. These are light and have semi symmetrical or even flat bottom wings.

I'll add that P-51s of most any size are a nose-over waiting to happen. Twins or mulit engines add another dimension of uncertainty and complexity to a beginner. Some planes just were not all that great in full scale and are no better in models like the Stuka and P-39 Aircobra (opinions vary but we are primarily talking about ones first or second war bird). Some flew well with care like the Corsair and Spit, and then some just flew well period like the Zero and P-47. All the rest fit somewhere in between IMO.