Rendering animation on iMac

I am just getting into Blender but I have a client who is sending me .obj and .mtl files and wants me to do a 360° 10 sec rotation of a medical testing workstation. I can import the .obj and add a plane for the floor and add a few lights and get a decent image. The question is in regards to outputting the 10 second animation. At 24 Frames/sec an Eevee render on my I7 4.2Ghz iMac takes just a few minutes for the 240 frames but if I want to use Cycles renders, its about 4 minutes per frame. I did change the tile size from 128 down to 32 and that reduced the output time in Cycles to just 50 sec.I could then create the 10 second animation in under 3.5 hours. I have account with RebusFarm and sent a test file through there, the results were a bit wonky for lack of a better word. Once I put all the frames into the Blender image sequencer the final result had images that backed up. Very strange.

I could probably stay with the animation from my iMac and live with a few hours rendering as opposed to using a render farm but I do have an HP Desktop I5 PC that I use primarily for accounting and testing PDFs and presentations. So the question is, would it be better to upgrade the graphics card in the PC and just use that as a render station and what card should I get?

Thanks

You can also reduce light bounces & pixel resolution to speed up render times. For CPU rendering, your tile size should be the smallest possible. So 8x8 tiles are faster than 32x32 tiles. You can also render every 2 frames, so your render takes half the time (at the cost of frame rate). And you can use much lower samples if you enable the denoiser. I’ve heard graphics card rendering is faster, but I’ve never tried.