D700 is good to begin with if you are setting aside more budget for lens. Bodies tend to drop in price faster too.
D700 is decent on ISO 3200 although the D800 would be better.
I didn't like the vertical grip for the D800 because it virtually is not value for money. for the D700, it can boost your Max FPS to 8 (I think) so that's a different story
UWA for full frame can be anything from the Samyang 14mm f/2.8, Zeiss 15mm f/2.8 or the ever popular Nikon 14-24mm f/2.8G or Nikon 16-35mm f/4G VR or Nikon 18-35mm f/3.5-5.6G. If you don't need f/2.8 and want something below SGD 1,000 to shoot at f/8 over the usual landscape range, the 18-35mm f/3.5-5.6G is the best value for money.
24-70mm f/2.8 - at least 2 options. Popular ones with known results are Nikon or Tamron. I don't own either so can't really comment but I understand that the Tamron is value for money. This is especially so if you also intend to own the Sigma 35mm f/1.4 A and a 70-200mm which covers 2 of the 4 key focal range of 24, 35 ,50 & 70mm, leaving you with 24mm and 50mm. Looking at lens test results, the Nikon 24-70 is weak at 24mm IMHO.
35mm - Well, I believe you read the tread I started. Sigma is the way to go.
85mm - I don't own one although I use the one my friend lends me on a frequent basis. There are lots of good reviews on the Samyang, Sigma 85mm f/1.4 that is a lot cheaper but almost just as good to a certain extend in the 85mm f/1.4 specifications. If you don't need f/1.4, get the Nikon 85mm f/1.8G. In our current day context, the Zeiss 85mm f/1.4 is a little too expensive with only MF and for me, I am not in love with the dreamy effect this lens produce at f/1.4 plus there is evident purple CA at f/1.4 so I won't recommend it.
80-200mm f/2.8 or 70-200mm f/2.8 - the best in this class is the Nikon 70-200mm f/2.8 VR II. It is the most expensive and cost over/near 3K in Singapore but you don't need to think about buying another lens in this range for many years to come. If you are covering sports and fast pace events, the 70-200mm f/2.8 VR II wont disappoint you and you can add the TC-14E II for reach and shoot it wide open at f/4. the bokeh is also very nice so you can use it for portrait shoots.
Been using Sony dslr for a few years and now I feel like changing to Nikon system. It's not that Sony is no good but it was unable to shoot at low light conditions.
I'm planning to buy 2nd hand Nikon D700 as it's quite affordable in the market.
Just want to ask should I get D700 or D800?
I'm planning to use max ISO of 3200 as I'm been shooting a max of ISO 800 using Sony as the noise was quite bad after ISO1200.
Secondly should I get a vertical grip?
Any good lens to recommend for full frame
My Planned lens range
xx mm (any good ultra wide angle, currently using Tokina 11-16mm for crop Sony)
24-70mm f2.8 (dunno which brand is good)
35mm f1.4​ (Sigma)
85mm f1.4 (dunno which brand is good)
80-200mm F2.8 or 70-200mm (dunno which brand is good)