The DLS A5 is a 2+1 channel amp so not with that one. The A2 is a 2 channel amp so no with that one either. The Arc KS500.1 is a mono amp so no luck with that one either. Now, the KS 300.4 is a 4 channel, so yes, you could potentially do it with that one. You would either need 2 2 channel amps or a single 4 channel amp with an active capable head unit or sound processor.
For a 2-way front, generally, yes. If you need more powa, bridging is always nice, but will need more channels of amplification to do so. Bridging will also give the benefit to balance L/R separately if you don't already have the processing to do so.
For a simple 2-way front + sub, you will need a 3-way xover (2-way front + sub = 3!). and no, the quantity of highs, mids or lows will not cause you to need more than a 3-way xover. ie. tweet, mids, and two or mor subs will still just need a 3-way xover.
1--High pass for highs/tweets (HP)
2--Bandpass for mids (HP+LP)
3--Lowpass for sub(s)
=1,2,3-way
soooo, for a 3-way ''system'' you'll need a minimum of 5 channels of amplification. 2 tweets + 2 mids + 1 sub = 5
3-way front + sub, will call for a 4-way xover
1--High pass for highs/tweets
2--Bandpass for midrange
3--Bandpass for midbass
4--Lowpass for sub
=4-way
a minimum of 7 channels of amplification is need for a 4-way "system"