SD card slots are common. CF card slots are rare and you would expect to carry an external adapter in that case.
DVI is fine. Newer laptops might have HDMI, but they use the same signalling so just get the right cable to connect between them and it should be fine.
On the number of cores, that does depend a bit of if the software you expect to use can make use of them. Most laptop CPUs, even higher end ones, are only dual core since they have to balance processing power with power consumption. Note the intel ones may be 2 core 4 thread, but that's still less than 4 core and 4 or 8 thread. Only the highest end laptops might have physical quad core as an option.
Graphics performance is more important than it has been in the past, even if you are not a gamer. They can be used to accelerate many types of processing, which is becoming ever more common. But like CPUs, there is a tough balancing act on power, so it is harder to find higher end solutions.
For future proofing, try to find one that supports USB3. Without that, there are the usual suspects like e-sata or firewire if you have devices that can make use of them.
Ram is cheap enough these days, even for a laptop. I don't think there is any good reason to get less than 8GB, unless the manufacturer sells it as an overpriced upgrade where it might be more economic to do it yourself later.
I can't suggest any specific laptop as there's simply too many out there to keep up with.
DVI is fine. Newer laptops might have HDMI, but they use the same signalling so just get the right cable to connect between them and it should be fine.
On the number of cores, that does depend a bit of if the software you expect to use can make use of them. Most laptop CPUs, even higher end ones, are only dual core since they have to balance processing power with power consumption. Note the intel ones may be 2 core 4 thread, but that's still less than 4 core and 4 or 8 thread. Only the highest end laptops might have physical quad core as an option.
Graphics performance is more important than it has been in the past, even if you are not a gamer. They can be used to accelerate many types of processing, which is becoming ever more common. But like CPUs, there is a tough balancing act on power, so it is harder to find higher end solutions.
For future proofing, try to find one that supports USB3. Without that, there are the usual suspects like e-sata or firewire if you have devices that can make use of them.
Ram is cheap enough these days, even for a laptop. I don't think there is any good reason to get less than 8GB, unless the manufacturer sells it as an overpriced upgrade where it might be more economic to do it yourself later.
I can't suggest any specific laptop as there's simply too many out there to keep up with.
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