Oddly enough just yesterday I was looking around trying to find a comparable option. I've been watching ebay for about two months, and made a few bids on SL5's but came up short every time, and I can only see that getting worse as Golite is now out of business...
Colonel00 definitely pointed you in the right direction!
I'm looking for something comfortable for 2 people for several days, with the option to add a third or a dog in the right circumstances. Down the road I'd perhaps like to add a stove, but that isn't super high on my list for the time being as I won't be heading to AK or too far North any time in the next year or two.
So, here's a few that jumped out at me...
MLD Duostar XL-
http://www.mountainlaureldesigns.com/shop/product_info.php?products_id=217
$325 for the body alone, or Ends up being $570 for the pyramid, and the optional floor and optional nest... I like the idea of having the nest for spring/summer to keep the bugs out, and still give you a large area(40"x104") of vestibule for cooking in and storing gear if need be. I also like the idea of running just a bathtub floor in it for some trips, this again leaves a large area of dirt floor open for vestibule storage. I can also visualize adding a small stove to one of the front corners down the road.
The body itself weighs 24oz, the nest 15oz, and the floor 9oz. So under 3 pounds for any way you set it up(minus pole).
Bearpawwd Luna 4 or Luna 5-
http://bearpawwd.com/tents_tarps/luna.html
$275/$335 body alone, with the option to add full Pyranet 4 nest for $150 more. These are a simple 4 sided pyramid shape. Weighs in at 29oz for the Luna 4 body, 36oz for the Luna 5 body, and then 19oz for the Pyranet. I'm sure that Bearpawwd could fab up a half liner(modified Pyranet2) like that of the MLD above.
The cheapest option might be the Oware Pyramid tarps-
http://shop.bivysack.com/Pyramid-Tarp-10x10-1Pyramid10x10.htm
$200-$240. They offer them in 8x8, 9x9, 10x10, and even 11x11. Decent weight, but it doesn't look like they offer floors or nests, so you'd have to head over to one of the above sites to get the accessories.
Seek outside and Kifaru's options are many, but they all fall a couple hundred dollars higher than the Golite SL5 was priced at...