er, to answer the question, bad idea. separate computer is 10000x better

the bitcoin node needs to stay on all the time and same with lightning, better to use a laptop and get a UPS and mobile network failover for your router then you can really run a reliable LN node

laptops do have a benefit in that they are very low power but very cheap on the second hand market, so, better to just buy a second hand laptop for the job imo, doesn't have to be very nice, 200 plus another 100 for a 1tb ssd