Unless you're pressed for time to get it running then you absolutely can swap the motor yourself, there's quite a variety of different infiniti/nissan vehicles that would make a suitable donor, FX35/EX35/G35/M35 I think all use the VQ35DE. In the meantime I'd get it up on jacks, pull off the lower oil pan and inspect the damage, if you're lucky it's only the short block that's cooked which REALLY broadens the donor list since I think ALL VQ35DE uses the same short block regardless of revup or non-revup. Start checking for people with a wrecked suitable donor, post it on facebook what you're looking for, same with craigslist, local want ad papers, call around to wrecking yards and local importers to see if they have low mile engines for a reasonable price.

Keep your entire ignition and fuel delivery system, intake manifold, throttle body, and all sensors since you know they're functional. Swap the long block if you find a suitable donor, if you can only find a short block donor then strip down to the heads, get them checked at a shop, reuse if needed, it's a little more work assembling from a short block but it's REALLY not hard, just follow the steps in the FSM or haynes/chilton, torque properly, buy a couple gaskets, done. This motor is cake to swap since the entire front end of the vehicle unbolts to allow easy access.

Keep track of ALL your nuts and bolts, ideally you would put them right back in the hole after you take a piece off but if that's not feasible just take a digital picture of how it looked before/after assembly with a sticky note that has a giant number on it, put the parts in a bag and write the number on the front of the bag in sharpie. That's been my go-to scientific method to keep track of stuff and it has NEVER let me down.

If that shop will do the swap including labor, engine, parts, fluids for $1250 that's a damned good deal depending on how many miles is on the donor motor.

 

So after reading and researching I'm going to install the engine myself. Doesn't seem to bad and it'll be a great learning experience and I'll also make a major write up for the site. There are a few engines around me that I've seen, lowest being 75k for 800.00 so I have some options.

So stay a tuned for updates because I'll be prepping the engine for removal in a few days.

 

Just make sure to plug all openings in systems with tape, things like the radiator, heater core, get the AC refrigerant pumped down (call around to AC repair shops, folks will usually come to you to do it if you give them the refrigerant for free), tape off the condensor, line set, etc. You want to limit the amount of condensation that makes it's way into stuff to keep corrosion to a minimum.

If you're having a hard time finding someone to reclaim the refrigerant don't limit yourself to just auto AC techs, call around to home AC shops, might be able to strike a good deal on the car and a system check for your home or something