MX & immediate implant reconstruction - how good is it?

I had a LWE last week, I’ve had no skin removed and the scar around my areola is quite neat. However I do have a noticeable dent where the tumour was removed that feels really hard and adhering to the tissue below, compared to the area around which is swollen but soft. Will this dent get better or worse? How I feel about this will determine my next stage of treatment…
If my nodes are clear & I don’t need chemo, then I’ll have to make a decision on local treatment - I think the choice will be to stay with what I’ve got left & have radiotherapy, or to have a full mastectomy with immediate implant only reconstruction (I was told this would likely give me the best cosmetic result, as I’m not big - 34B originally). From what I’ve read on here, the rads are likely to make my breast tissue more fibrous & possibly some tissue shrinkage. If I go for the MX & recon, how good a result will I really get? Will I still look obviously lop-sided? I’d appreciate any advice from people who’ve gone through this.