Costs of designing, building and molding the jet would be significantly higher than buying a trainer... even doing it all yourself.

Do some searches on the net for the Altech TameCat. Its a trainer designed to look like an F-14. (remarkably good appearance... I covered mine in green/brown camo top, blue belly.) Unfortunately, the kit is discontinued... but some may still be on shop shelves. After much experimentation, I found that when using a TT .46 Pro engine, the APC 12.25 X 3.75 is the best propellor for the plane (requires lengthening the nosegear and bending the mains to have clearance from the ground) I wouldn't put a weaker engine on it. The "kit" was available in "ARC" (almost ready to cover) or ARF versions.

The TameCat, or buying a trainer kit and modifying the fuselage to resemble it would be the best option to meet your desire of a jet appearance in a first aircraft. (wing only gets changed in the aileron torque rod length and a slight loss of center "span" by having a wider fuselage... which actually adds lift!) Many trainer kits could be modified this way.... Not too hard either. But it does limit you to NOT getting an ARF.