Here's the link to the Mustang you are referring to:

[link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=HAN2825]Hanger 9 P-51 Mustang PTS[/link]


Now here is the rest of the list of 2nd planes that Bruce referred to.

Intermediate or "Second" planes.
This is kind of a "fuzzy" area. For some pilots these planes will be second planes, meaning that they will move on to them after they have soloed on their trainers. While other pilots that have more "natural" talent may be able to use these planes to learn to fly on.
Whichever category you fall into please be aware that these planes are more of handfull to fly than the basic trainers listed above. While these planes my be very docile to fly many of them lack the "self righting" properties of the traditional trainer. Use of these planes as a trainer should be a matter that you take up with your instructor, as he will be the one to best judge your talents and abilities.

Kits
[link=http://www.btemodels.com/venture.html]Bruce Thorpe EngineeringVenture 60 [/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFG06&P=0]Sig Four-Star 40 Kit .30-.40,59.75"[/link]
[link=http://sigmfg.com/cgi-bin/dpsmart.exe/ProductsV5.html?L+Sig+ljsg7633+_Ddp_5fSearch1_02A_ 2dPlaneRCFStar60_01Search_02Index_01SubMenu_02None _01]Sig Four-Star 60 Kit 60-.75 in, 71"[/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFG07&P=7]Sig Mid Star 40 Kit .30-.40,64.5" [/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXDJC9&P=0]Goldberg Tiger 2 Kit .40-.46,61"][/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXDJD4&P=0]Goldberg Tiger 60 Kit .45-.65,70"][/link]

ARF's
[link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=HAN2625]Hanger 9 Arrow .40 Semi-Sym Trainer ARF[/link]
[link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=HAN2845]Hanger 9 P-51 Mustang PTS ARF[/link]
[link=http://sigmfg.com/cgi-bin/dpsmart.exe/ProductsV5.html?L+Sig+ljsg7633+_Ddp_5fSearch1_02B_ 2dPlaneRC_264Star40_01Search_02Index_01SubMenu_02N one_01] Sig Four-Star 40 ARF 40-.53 in. 59.75"[/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCHY3&P=0]Sig Four-Star 60 ARF Red .60-.75,71"[/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXH755&P=0]Goldberg Tiger 2 ARF .40-.46,61"[/link]
[link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=HAN4100]Hanger 9 Pulse XT[/link]
[link=http://www.airborne-models.com/html/productdetails.asp?ProductID=16]World Models Sky Raider Mach II S[/link]


Hope this helps

Ken