In short - fugedaboudit! All that trike amounts to is a very heavy adult version of a "Big Wheel", and motorizing the front wheel of that thing will be a disaster - no freewheel to be had! But, if you are into 'spinning' and can figure out a way to mount "Spuds" (clipless pedals), go right ahead - bet ya it'll take you right on up to 150 rpm, prolly lots more more! Fun till your spud releases and you get "leg suck". If you are looking for a low cost, solid trike to build on, check out the Terra Trike" line or the Sun Tadpole or delta line.
Seriously, folks - there are a lot of really good recumbent trikes being made now, some available in the $1000 - 1500 range. You are much better off waiting until you can afford a strong, low frame frame rather than buying a trike that was made to take granny and grampy down to the Sr. Citizen center for the daily bingo game - because that is what the Miami Sun trikes were designed for! Not for fast riding and stopping, motorizing or handling! This from a 63 y/o senior citizen trike rider and sportscar racer who still likes going fast.