Outside terminals (DOTS) are POSITIVE, inside terminals (STRIPS) are NEGATIVE.
It should be fine to get same capacity of 1000 uF. I have 4500 uF soldered with no effect over 1000 uF.
When using several caps you reach lower overall ESR which is good. Also, resonance frequencies differ between several caps and that may have some positive effect in very specific circumstances.
Any cables affect ESR, the shorter the connection the better.
The cap on your link is some kind of educational one with no description and you better skip it.
Look for tantalum caps, rated 6.3v (G rating) - these are small enough to solder 2-3pcs of 330uF on board directly and still fit the space below mb cooler.
@Yoshiaski make sure you notice edit - outside is positive, inside is negative.