Well, if you aren't going to build it yourself the SSD will increase the price on a custom laptop quite a bit.
One of the more popular ones available right now is the HP Envy 15t 15.6" laptop at:
http/www.shopping.hp.com/en_US/home-office/-/products/Laptops/HP-ENVY/G0T95AV?HP-ENVY-15t-Laptop
If you want an SSD, you can get a 256GB model, but that also requires that you get an NVIDIA GPU (as it comes with the low power Intel i7 CPU).
I customized one for $955 that has the following:
Windows 8.1 x64
Intel i7-4510U CPU with
NVIDIA GeForce 840m GPU (middle option on CPU selector)
8GB RAM
1920 x 1080 display (higher resolution than default)
256GB Flash Solid State Drive
802.11b/g/n WLAN and Bluetooth® [1x1] (HP seems to hate Bluetooth, so it is optional)
Quick note - given the video card, this laptop can game using at least medium settings, and some games at high settings.
Not a bad deal, but still pretty expensive. As always with laptops, ideally you would try one out first that is in the same series (Envy 15t) before you decide to purchase one.
I think that the 15.6" size is ideal for a laptop that you want to use on the go. A 17" model may be fine if you plan to treat it more like a desktop and not tote it around very often.
Other custom laptop vendors can also deliver ones that meet your specifications, but it is unlikely that you will find one to try out unless you know someone that has one (like Sager or MSI).