May I ask, is there a particular reason you prefer a VPS over a dedicated server? Our VPS packages at
XenLayer go up to 4 GB by default, but I can double your allocated cores (Intel Xeon E5645 2.4 GHz) and add burstable memory at a slightly higher price on OpenVZ. Anything over 8 GB (either Xen or OpenVZ) would be more expensive than our Intel Core2Quad 2.5 GHz w/ 8GB DDR3, I'll add a second 1TB SATAIII drive and put it in a RAID config for free.
Full management is included, we will monitor the services on your machine and perform periodical upgrades, patches and checkups. We also support and have experience with Nginx configurations and can tweak your server for maximum efficiency.
Hit me up with the specs and I will give you a good deal, or simple use the coupon XENLAYER10OFF for a 10% off for life.