Well done on doing your homework!
I'd say, on top of the critical care, get some fibreplex or similar (probiotic but also firms up faeces) to give alongside the antibiotics, and also some soluble vit C tablets if you dont have them already (Jeff needed them and went bananas over the orange flavoured ones rolleyes). I now keep these things "in stock" as they are handy commodities to have in the event of an unwell piggy over night. The last thing you want is to bring him home, and find hes not eating after the vets close!
One of my trio came to me already neutered, I had the two Daves neutered by my local vet, no problems at all, but then, I didn't expect there to be any - he's a small animal specialist, and I've worked with him several times over the years and he's an incredibly accomplished surgeon. Post op check after 2, 5 and 10 days. No antibiotics given, although Big Dave did develop a snuffle after the anaesthetic so they gave him some Baytril as a precaution.
Jeff however, was neutered by the RSPCA (They will never touch another one of my animals!) and looked like he'd been butchered. The incisions were uneven - one was three times the length of the other, and he was badly glued back together, which was a potential risk with healing. They sent him home with some baytril to be used for 5 days, but the wrong dose mallethead They also did a dental exam on him while he was under GA (due to his missing teeth etc) and his vet notes said that he had lost his canine teeth rolleyes
I took him to work for his post op checks, again, seeing small animal specialists that I trust, and he had a post op check at 3 days, 10 days, 14 days, 21 days and 28 days, as they were concerned about his stupidly large wounds and his dodgy glue job. He was on Baytril for this whole time (at the correct dose!) along with fibreplex. He was ok in himself, and eating like a horse straight away afterwards, despite having no teeth rolleyes
I'd recommend that you have post op checks more frequently than 1 week and 1 month. They will be fine with this at the vets, it's just a case of a nurse looking at it, and getting an opinion from the vet if he/she has any concerns. Where I work, its routine to have a POC after 3 days and 10 days, and then as necessary afterwards - by all means keep the 4 week appt, they seem like they know the potential for complications when it looks like it's all healed.