I realise you're new, and you seem to have a fetish for spamming the forums. But your answers mostly indicate you don't know what you're talking about, and are simply making it up.
Any other medium jet that's available new will be a better choice at this stage of MT.
The f70 carries 70 pax, 1840 NM, 560k/month to lease a new one. The equivalent COMAC ( http://www.airwaysim.com/game/Aircraft/New/View/355/
in MT) carries more pax, has more range, burns less fuel overall, and is 75% of the price.
There is a longer range version, maybe he absolutely needs that extra 170 NM, out to 2010. So, 70 seats, 2010 range, just over 600k/month to lease. The Sukhoi 100-75 has 70 seats, 2300 NM range, costs under 500k/month, and uses 25% less fuel.
The best f100 carries 105 pax, 1630 range, 650k/month to lease. The equivalent E195 carries 104 pax, 1630 range, at least 10% less fuel, at least 20% less in maintenance, over 8% cheaper to lease.
So, it's 2012 in MT, and when it comes to new planes, the F70/F100 are definitively worse in all respects than their direct competitors. Don't buy them.
@OP: There usually isn't a 'best' plane, a definitively correct answer. Have a look at the new plane lists yourself. Look at the range, the seats, the speed and the fuel costs. Compare the planes that look like they might fit. Do you really want more range? Do you really want 100+ seats? Do you really want the cheapest leases? Then work out which one you want. Making money on 50 seat, 1900 NM routes with fuel at $1000+ will be tough, though.