Hello to all

I need help to decide what spec to buy.

Requirements: run solidworks efficiently. up to about 500 parts assemblies. no rendering, no shading, just machine design.

I "narrowed" it down to 4 very different options(its expensive here i know):

1. A simple Dell Latitude 3440. i5-4200U, 4GB RAM, integrated graphics 4400:   770$

2. Lenovo Y510P. i7-4700MQ, 8GB RAM, GT750M graphics:   1280$

3. Dell Precision 2800. i5-4200M, 8GB RAM, Firepro W4170M graphics:   1800$

4. Dell Precision 2800. i7-4810MQ, 8GB RAM, Firepro W4170M graphics:   2140$

The reason for the wide variety is, im not sure the extra cost is justified given that up until now i was perfectly satisfied with my desktop's GT630 graphics, Q6600 processor and 4GB RAM (but i have worked on assemblies with up to about 200 parts).

I know the formal response is "get a quadro/firepro", but up until now i never needed one, and the cost delta is considerable.

Right now im leaning towards the Y510P.

Every input will be much appreciated,

Guy