from what I have seen of the parkzone planes, adding gear would take some work,needing to add a solid mount for the gear in the wing since the foam construction is not the strongest base to handle the stress of the wire landing gear,the ones I have seen do not have the strongest wings and are built to be light weight .

hear is a reality check, your not going to be ready for the Top Flight Corsair, flying a parkzone plane it doesn't transfer as far as the skills needed,a real warbird is heavy, needs to be flown into the landing, and more likely than not has flaps,to control landing approach speeds .
you might as well invest in a simulator and fly the advanced planes there to increase your proficency with the sticks,learning the basics of flaps,retractable landing gear,using the rudder,and landing a fast heavy plane, and you will also have a large variety of planes to try with the sim, for the price of the parkzone plane.
you will need to learn basic landing skills, and when you do get these wired on a sim you can ramp up the wind and the enviroment and challenge yourself without having to pay heavy dollars to replace your crashes.

if your serious about learning to fly advanced planes like warbirds then your going to have to strive for that type of plane,a sig something extra or something in that type,a tail dragger,light weight so it flys easy and doesn't sink out of the sky, so you can transfer that sim time into real world practice,it doesn't matter what power source you chose as long as its enough to power the plane your flying.

the reason I recomended the Hangar-9 planes was its in the general size range of the kit your working towards finishing,same power requirements,retractable landing gear and is alot lighter so its more forgiving in the air,with good slow flying charictaristics,that means the wings don't want to tip when your coming in slow for a landing,something the Top flight doesn't have,you are going to have to be on your toes to fly that one.

between the simulator and help from my flying club members flying warbirds has become my prefered type of plane,my engine choice for 60 size warbirds is a OS 91-120 4stroke great power source for the size plane,it really depends on your skill set and your budget a typical warbird like your TF is going to cost 500-1,000$ depending on your finishes and weather or not you chose retractable landing gear, a arf like the H-9 closer to the lower range, a kit build towards the top end.

just some information and suggestions to get you heading in the right direction.