Well, you could either do quick-connects, compression fittings, or barbs, to tubing, and then to the four valves. Or tubing to two of them, and the valves to the other two.
Or you could add extensions and elbows, any which way (up/down/up/down, for example).
Or you could plug up the two middle ports and add tees to the first and fourth port, and run two valves from each tee. This might be the prettiest - or, at least, least ugly - and yet still fairly compact.
But you're going to want a solenoid before the mainfold. No timer to four tanks is a huge waste.