Silver Cross Dream no - that's only Silver Cross compatible.
Generally, ignore the ages they say they go up to and look at type of seat. The type of seat you need for a travel system is an infant carrier. It will usually say it's suitable from birth up to usually 12-18 months or so, I think Cybex say 2 years, and the other way you can identify them is they have a carry handle (hence "infant carrier")
Egg do a car seat of their own called the Shell. That's worth a look if you like the matching look with the fabrics.
Otherwise it will take most of the popular brands - Cybex, Maxi Cosi, Britax, Besafe. Joie fit the same connectors (apart from Juva) if you want a more budget friendly model. Avionaut also go onto the same connectors and their infant inserts are especially good.
In terms of the ages they say they go up to, you get a range between 12 months and 24 months. In practice, ignore this because the amount of time you can use it actually depends on three things-
- What's the height limit. If it's 75cm then the seat is unlikely to last all the way to 12 months. If you're expecting an especially big/tall baby it might even be outgrown by 6 months or so.
- A height limit of 80cm+ should get you past a year but it doesn't really make much difference if it's 83/85/87cm - it's more likely you'll reach the physical limit of the seat first.
- How long is the shell - you have to stop using an infant carrier once the baby's head gets to the top of the seat. If you really want the longest lasting seat, take a tape measure and measure all the seats in the shop.
- When you get fed up of carrying the heavy lump of a baby which normally happens by the time they get to about 9kg (about 9 months). OR when they can stand up independently (which means there's less value in being able to place the seat on the floor) OR when they get fed up of lying in a reclined position and want to sit up and see out of the window.
In reality a lot of people change to the next stage of car seat by the time their baby is about 9-10 months old, sometimes if they get the rotating base, keep it until about 18 months, so to be perfectly honest, I wouldn't go all out spending a huge amount of money on this seat. There are some scenarios you might want to keep this type of seat for as long as possible e.g. when you don't have your own car. But for most people this doesn't apply.
The next type (fixed in the car, with integrated 5-point harness) is suitable from approx 6 months and lasts until ~4 years or ~7 years whichever type you have and you can't "skip" this type even if you have the biggest possible infant carrier because they will still be too young/small to go into a high back booster with adult seatbelt.