I think, you face a very tough question.
I have been hanging around this forum for a long time. The number of Toyota engine failures is a little frightening. You had your motor for about 3 years and it grenaded. You should do a post-mortem, but 260hp and 3 year life-span would point to some poor design decisions. I do not think, it was anything you did or could have done. It just reached a stress limit on some part....
I think one can build a Toyota engine properly. There are plenty of people on this forum that are running them. I think it would take some $$ and experience to do so. With aftermarket supercharger kits, you could get 400hp. My personal opinion is that somewhere between 300 and 400hp is a very nice place for a Lotus.

For me 550+hp is about right.
Engine: Building a 2ZZ or a K20/24 to the same level would cost a similar amount of $$. The K would be cheaper. The K is 10% to 25% more displacement! The weight is about the same. A k24 with stock block/cams/crank and forged pistons and rods would run 400hp all day long for a long time. Whatever $$ you save on the Honda will go into a Hondata computer with the Lotus dash interface and aftermarket engine mounts.
It would not be hard to build a 350hp NA 2.4L motor. It would be very easy to run a mildly turbocharged or supercharged motor to 400hp with stock cams, but maybe better valves.
Take a look at k20a.org in the engine section for common engine builds and results. the numbers I am quoting are very conservative with near Honda OEM reliability. The Odysey and MDX turbo motor is 260hp stock.
Then the Honda motor will have issues with adapting A/C (do you have that in the Cup car?) and cooling hoses. The cooling system can be easily re-made in AN hardware or adapted. I do not know what people have done about A/C.
There is a Honda conversion thread on this forum. There is my Widebody thread, although it is a pure race car.
Transmission: I think is the most complex part of the swap and the least reliable. Especially the shift cable adapter. In either cases, the cabling and shifting can be solved with a sequential from Quaife. The Honda kit is L4k. I am putting one in next week, so will put it back in the car and on the dyno in a few weeks and report. Additional items beyond that:
1. Axles. $1k
2. If you are making new axles, might as well modify the hub and the bearing, just like me and safely run 11" or 12" slick.
3. Shift cable adapter $1k, if you run stock Honda tranny.
4. Clutch.
5. New through-out bearing, although Honda slave cylinder arrangement can be re-used.
Exhaust: You will need new exhaust or parts of thereof. This could cost some $$.
The last question is the value of your car as it came from the factory. Ir will loose value with a Honda motor. Also, you have a large investment in Toyota hardware, unless it is all blown up!
Please, tell us how you managed to register this car in the US. You can PM me and I live in Canada...
Good Luck! Just take this as an opportunity to step up to 400hp! or more!
Anton