1. Poland already had a good tank, the 7TP. No need for Czech ones.Perhaps between them they could develop a competitve fighter to completment that bomber the Pole built, and they could certainly utilise the good Chzech tanks.
2. Aircraft wise:
a) the bomber you mention is most likely PZL.37 Los - it was just being put into frontline use by the end of 1938... and it had some nasty bugs to hammer down (lost around a dozen in crashes)
b) the lack of modern Polish fighter can be pinned down to the choice of Bristol engine license in 1930. If instead Wright engine was chosen instead, in 1938 Poland would probably have sth like 100 PZL.24 analogues (4MG, 430km/h top speed - not bad, considering that Bf 109 C/D had 440/460km/h top speed and the same armanent).
Hmmm. Also considering that Germany would have in the above scenario to deal with Poland and Czechoslovakia at the same time, Wehrmacht, I think, would put most of its forces against Poland...