From what I've read about this potential race, Trump was for the most part gonna walk away with the Reform nomination; he had the support of many from both sides of the aisle in the Reform Party, but in many cases, it was simply because they saw him as a better alternative to Buchanan & Hagelin, not because they actually supported him. And, with Trump as the clear favorite to win the Reform Party's nomination, Buchanan probably never makes a play for it & instead goes for the Constitution Party's.
As for the general election, well, I can't say much because I don't think Trump really thought all that far ahead. As an example, he thought that Oprah would make a good running mate for him; don't know how that would've gone, & I doubt she would've accepted. If he wants a credible running mate, preferably with political experience & from another part of the country, then I'm thinking Richard Lamm, former governor of Colorado. At the end of the day, I'd wager that he does better than Nader but worse than Perot in 1996; he'd have a similar effect to Nader, but considering he'd be better funded, it'd probably be worse for the GOP in terms of how he'd have acted as a spoiler for them.
Gore wins, yay.
Gore/Lieberman: 292 EV, 46.2%
Bush/Cheney: 246 EV, 44.5%
Trump/Lamm: 0 EV, 5.7%
Nader/LaDuke: 0 EV, 2.7%
Buchanan/Foster: 0 EV, 0.3%
