Regarding reconstruction, it is a very personal decision and everyone should be entitled to have or not have it and, if the former, in a timely manner. So I can only speak for myself, but my experience may be useful if not sure about DIEP vs. implants.
There are, as with everything, pros and cons to each. DIEP is a bigger surgery and leaves you with more scars. The additional scars are something one tends not to be prepared for, as the focus is all on the breast. I was somewhat taken aback by this. They do (I am told) fade with time and sensation along the scar should come (at least partially) back, but it does involve adjusting to a slightly changed abdomen as well as the changed chest.
I had DIEP as an immediate reconstruction. A friend of mine had implants - which her body rejected a couple of years later and eventually got fed up with endless attempts to salvage them and replace, and decided to go flat. This served as a cautionary tale to me (though it is of course just one person's experience). My DIEP breast has so far held up well, is very close in shape and size to my other natural breast (well, I can see a difference, but then perfect symmetry does not even exist in natural breasts, so this is pretty damn close enough). It feels very soft and now four months post operation, feels like 'my' breast. There is some lack of sensation but it moves not too differently from the natural breast, the texture is similar and it is warm to the touch, so feels like part of me now (which of course in a way it is). I would like to have my nipple reconstructed so that I can go bra-less under a T-shirt again (I have never been a fan of wearing a bra), but in terms of body image, I am ok with it as it is already, so don't mind waiting for the nipple. In reference to second surgeries, some surgeons manage to get things close to right the first time, so you won't necessarily need symmetrisation surgery. They work out the size of the reconstruction based on the the weight of the mastectomy, so it can end up being very much the same weight/size as the breast they removed first time round, avoiding the need for surgery later (unless there is not enough tissue to take from the abdomen and they need to reduce the natural breast, say). So, in my experience DIEP has not been too bad and is worth it (out of the range of sub-optimal choices available), with the caveats above and provided of course there are no complications (something so unpredictable - in my case the 8 hour breast reconstruction caused very little post surgical problems compared to those that followed from the lymph node biopsy - go figure).